Sony KV 1515 flashy picture

[Keith Park]

had this since new, was sitting, took it out and had no audio and a picture that has lots of horizontal lines and blocks of flashy in the picture, sometimes the picture will go to garbled color, found an open resistor and fixed the sound, but the flashing goes on, unplugged the tuner, same, so thats not it... cant find any bad solders, doesnt act physical, no leaky caps... ideas? working without a print on this one too.

Thanks

Keith

[damen]

Used to have to clean just about every trim pot control mounted on the circuit boards on those sets. AGC, AGC delay, B+, horizontal frequency, pin cushion, sub hue, ACC, video drives, and any others that I saw.

[zeno]

Its in Sams 2041-3
BUT this set may be one that had two different chassii. The audio
out was the big difference. So it may be best to look up
the chassis ##.
As far as problem goes can you put up a video of it ??

73 Zeno
LFOD !

[Keith Park]

I cleaned the controls, still bad, it flashes between a normal picture and a very dim washed out one with reds and blues only, yea.. the green gun is still working. where and what do I look for chassis number on these?

thanks

Keith

[Keith Park]

add green to that washed out picture...
removing and putting back a video signal seems to have some affect in making it happen and stick, can be stable in either mode for a while but pull the cable off the back and it acts up quickly again. Tough dog! not a physical intermittent...

[zeno]

Chassis number usually on the CRT shield. Starts SCC-###
Set uses apx 200 V on the 3 video output transistors. A little cap,
usually 4.7 mfd 350V is on that 200 V line If you can trace it out try
it. VERY common on all brands. May be on the CRT socket or main
board near the HV transformer.

Good luck

[Keith Park]

its and SCC 350A-A

no ecaps greater than 160V, except for the big filter cap on the power supply and thats only 200V

Keith

[zeno]

A little different.
Look for C540 & C541 they are in front of the flyback.

Zeno

[Keith Park]

Changed out those two, still bad. more of a hard failure now to that dark washed out mostly red and blue picture, a little green in here and there but no fleshtones or anything like that and poor focus too. Its almost as if an oscillator somewhere in the chroma section is cutting out... been too many years since Ive done these, and well... back then the Sony's of this era never died!

[zeno]

Whats it look like with no signal ?
You can check the 3 cathodes should be in the 180-190 area.
G-2 about 500 V, focus 300 V
Did this happen over time or sudenly ?

[Keith Park]

with no signal its kinda a dark snow, flashy if its flipping back and forth between OK and problem... Ill check those. Set sat 10 years or more, did this when I turned it on for the first time. The audio was out too, but an open resistor in that section was the culprit and thats replaced and works fine now.
Thanks

Keith